---
title: "Environment Variables"
sidebarTitle: "Environment Variables"
description: "Useful environment variables to configure Subtrace"
icon: "sliders"
---

Subtrace can be configured with the following environment variables.

## `SUBTRACE_TOKEN`
Secret token used to authenticate with the Subtrace dashboard. Recommended but optional. Without this, each `subtrace run` invocation will generate a new, ephemeral dashboard URL.

## `SUBTRACE_PAYLOAD_LIMIT`
Max bytes captured for request/response payloads. Defaults to 4096 bytes. Set `SUBTRACE_PAYLOAD_LIMIT=65536` to debug larger payloads, for example.

## `SUBTRACE_TLS`
Intercept outgoing TLS. Default enabled. Set `SUBTRACE_TLS=false` to turn off TLS interception if you face TLS issues.

## `SUBTRACE_HTTP2`
HTTP/2 capture control. Default enabled. Set `SUBTRACE_HTTP2=false` to disable if you face HTTP/2 issues.

## `SUBTRACE_WEBSOCKET`
WebSocket capture support (experimental). Default disabled. Set `SUBTRACE_WEBSOCKET=true` to enable.

## `SUBTRACE_WEBSOCKET_TIME_LIMIT`
When WebSockets are enabled, optional time limit (seconds) for long‑lived streams. Default ~110s.

## `SUBTRACE_LINK_ID_OVERRIDE`
Override the ephemeral link ID when no token is set. Mostly useful for automation and demos.
